1. Field of the Invention
The invention relates generally to apparatus having structured surfaces and methods of making and using such apparatus.
2. Discussion of the Related Art
Conventional micro-fabrication techniques have produced silicon surfaces patterned by regular arrays of high aspect-ratio nanostructures. In exemplary arrays, the nanostructures are vertical posts with heights of between a few micrometers and a few tens of micrometers and diameters of about a micrometer or less. Neighboring ones of the posts are, e.g., separated ten micrometers or less.
These conventional arrays of high aspect-ratio nanostructures can qualitatively modify a substrate's wetting properties with respect to aqueous solutions. An array of such nanostructures can, e.g., cause the surface of silicon substrate to behave as a super hydrophobic surface. A super hydrophobic surface produces a large contact angle to a water droplet located thereon and causes the droplet to be highly mobile. Super hydrophobic surfaces have had a variety of applications.